That was until another howler from the match officials saw the Blues awarded a penalty that never was in the dying seconds of the game.
It wasn't the only controversy either.
Fabregas stepped up and converted the free-kick, made all the easier for him with West Ham's wall completely powerless to stop it.
West Ham fans and boss Slaven Bilic were furious after the game particularly given they were already feeling hard done by after poor decisions stopped them earning a place in the FA Cup semi-finals during a 1-1 draw with Manchester United at Old Trafford.
Now the club's co-owner Sullivan has spoken out about the issue on West Ham's official website, and he has a surprisingly considered take on things.
Paying the penalty
"It clearly wasn't a penalty on television, but nobody can blame the referee for getting such a marginal decision wrong in real time rather than a slow motion TV replay," Sullivan told whufc.com.
"What hurts me is we get no such marginal calls our way.
"The Dimitri Payet penalty at Manchester United could easily have been given and there are a dozen occasions this season where we could have got penalties and didn't."
Sullivan also highlighted that the Irons have not had an away penalty in the league for four seasons and have had less penalties in four seasons than any other team in the Premier League.